Reputation: 185
This is my schema:
mysql> describe stocks;
+-----------+-------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-----------+-------------+------+-----+---------+----------------+
| id | int(11) | NO | PRI | NULL | auto_increment |
| symbol | varchar(32) | NO | | NULL | |
| date | datetime | NO | | NULL | |
| value | float(10,3) | NO | | NULL | |
| contracts | int(8) | NO | | NULL | |
| open | float(10,3) | NO | | NULL | |
| close | float(10,3) | NO | | NULL | |
| high | float(10,3) | NO | | NULL | |
| low | float(10,3) | NO | | NULL | |
+-----------+-------------+------+-----+---------+----------------+
9 rows in set (0.03 sec)
I added the column open and low and I want to fill up with the data inside the table.
These values open/close are referenced to each day. (so the relative max/min id of each day should give me the correct value). So my first insight is get the list of date and then left join with the table:
SELECT DISTINCT(DATE(date)) as date FROM stocks
but I'm stuck because I can't get the max/min ID or the the first/last value. Thanks
Upvotes: 0
Views: 34
Reputation: 185
Solved!
mysql> UPDATE stocks s JOIN
-> (SELECT k.date, k.value as v1, y.value as v2 FROM (SELECT x.date, x.min_id, x.max_id, stocks.value FROM (SELECT DATE(date) as date,min(id) as min_id,max(id) as max_id FROM stocks group by DATE(date)) AS x LEFT JOIN stocks ON x.min_id = stocks.id) AS k LEFT JOIN stocks y ON k.max_id = y.id) sd
-> ON DATE(s.date) = sd.date
-> SET s.open = sd.v1, s.close = sd.v2;
Query OK, 995872 rows affected (1 min 50.38 sec)
Rows matched: 995872 Changed: 995872 Warnings: 0
Upvotes: 0
Reputation: 2159
You will get day wise min and max ids from below query
SELECT DATE_FORMAT(date, "%d/%m/%Y"),min(id) as min_id,max(id) as max_id FROM stocks group by DATE_FORMAT(date, "%d/%m/%Y")
But other requirement is not clear.
Upvotes: 1